/*
 * [The "BSD license"]
 *  Copyright (c) 2010 Terence Parr
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *  1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *      derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.antlr.tool;

import org.antlr.analysis.Label;
import org.antlr.grammar.v3.AssignTokenTypesWalker;
import org.antlr.misc.Utils;
import org.antlr.runtime.tree.TreeNodeStream;

import java.util.*;

/** Move all of the functionality from assign.types.g grammar file. */
public class AssignTokenTypesBehavior extends AssignTokenTypesWalker {
	protected static final Integer UNASSIGNED = Utils.integer(-1);
	protected static final Integer UNASSIGNED_IN_PARSER_RULE = Utils.integer(-2);

	protected Map<String,Integer> stringLiterals = new TreeMap<String, Integer>();
	protected Map<String,Integer> tokens = new TreeMap<String, Integer>();
	protected Map<String,String> aliases = new TreeMap<String, String>();
	protected Map<String,String> aliasesReverseIndex = new HashMap<String,String>();

	/** Track actual lexer rule defs so we don't get repeated token defs in
	 *  generated lexer.
	 */
	protected Set<String> tokenRuleDefs = new HashSet();

	public AssignTokenTypesBehavior() {
		super(null);
	}

    @Override
	protected void init(Grammar g) {
		this.grammar = g;
		currentRuleName = null;
		if ( stringAlias==null ) {
			// only init once; can't statically init since we need astFactory
			initASTPatterns();
		}
	}

	/** Track string literals (could be in tokens{} section) */
    @Override
	protected void trackString(GrammarAST t) {
		// if lexer, don't allow aliasing in tokens section
		if ( currentRuleName==null && grammar.type==Grammar.LEXER ) {
			ErrorManager.grammarError(ErrorManager.MSG_CANNOT_ALIAS_TOKENS_IN_LEXER,
									  grammar,
									  t.token,
									  t.getText());
			return;
		}
		// in a plain parser grammar rule, cannot reference literals
		// (unless defined previously via tokenVocab option)
		// don't warn until we hit root grammar as may be defined there.
		if ( grammar.getGrammarIsRoot() &&
			 grammar.type==Grammar.PARSER &&
			 grammar.getTokenType(t.getText())== Label.INVALID )
		{
			ErrorManager.grammarError(ErrorManager.MSG_LITERAL_NOT_ASSOCIATED_WITH_LEXER_RULE,
									  grammar,
									  t.token,
									  t.getText());
		}
		// Don't record literals for lexers, they are things to match not tokens
		if ( grammar.type==Grammar.LEXER ) {
			return;
		}
		// otherwise add literal to token types if referenced from parser rule
		// or in the tokens{} section
		if ( (currentRuleName==null ||
			  Character.isLowerCase(currentRuleName.charAt(0))) &&
																grammar.getTokenType(t.getText())==Label.INVALID )
		{
			stringLiterals.put(t.getText(), UNASSIGNED_IN_PARSER_RULE);
		}
	}

    @Override
	protected void trackToken(GrammarAST t) {
		// imported token names might exist, only add if new
		// Might have ';'=4 in vocab import and SEMI=';'. Avoid
		// setting to UNASSIGNED if we have loaded ';'/SEMI
		if ( grammar.getTokenType(t.getText())==Label.INVALID &&
			 tokens.get(t.getText())==null )
		{
			tokens.put(t.getText(), UNASSIGNED);
		}
	}

    @Override
	protected void trackTokenRule(GrammarAST t,
								  GrammarAST modifier,
								  GrammarAST block)
	{
		// imported token names might exist, only add if new
		if ( grammar.type==Grammar.LEXER || grammar.type==Grammar.COMBINED ) {
			if ( !Character.isUpperCase(t.getText().charAt(0)) ) {
				return;
			}
			if ( t.getText().equals(Grammar.ARTIFICIAL_TOKENS_RULENAME) ) {
				// don't add Tokens rule
				return;
			}

			// track all lexer rules so we can look for token refs w/o
			// associated lexer rules.
			grammar.composite.lexerRules.add(t.getText());

			int existing = grammar.getTokenType(t.getText());
			if ( existing==Label.INVALID ) {
				tokens.put(t.getText(), UNASSIGNED);
			}
			// look for "<TOKEN> : <literal> ;" pattern
			// (can have optional action last)
			if ( block.hasSameTreeStructure(charAlias) ||
				 block.hasSameTreeStructure(stringAlias) ||
				 block.hasSameTreeStructure(charAlias2) ||
				 block.hasSameTreeStructure(stringAlias2) )
			{
				tokenRuleDefs.add(t.getText());
				/*
			Grammar parent = grammar.composite.getDelegator(grammar);
			boolean importedByParserOrCombined =
				parent!=null &&
				(parent.type==Grammar.LEXER||parent.type==Grammar.PARSER);
				*/
				if ( grammar.type==Grammar.COMBINED || grammar.type==Grammar.LEXER ) {
					// only call this rule an alias if combined or lexer
					alias(t, (GrammarAST)block.getChild(0).getChild(0));
				}
			}
		}
		// else error
	}

    @Override
	protected void alias(GrammarAST t, GrammarAST s) {
		String tokenID = t.getText();
		String literal = s.getText();
		String prevAliasLiteralID = aliasesReverseIndex.get(literal);
		if ( prevAliasLiteralID!=null ) { // we've seen this literal before
			if ( tokenID.equals(prevAliasLiteralID) ) {
				// duplicate but identical alias; might be tokens {A='a'} and
				// lexer rule A : 'a' ;  Is ok, just return
				return;
			}

			// give error unless both are rules (ok if one is in tokens section)
			if ( !(tokenRuleDefs.contains(tokenID) && tokenRuleDefs.contains(prevAliasLiteralID)) )
			{
				// don't allow alias if A='a' in tokens section and B : 'a'; is rule.
				// Allow if both are rules.  Will get DFA nondeterminism error later.
				ErrorManager.grammarError(ErrorManager.MSG_TOKEN_ALIAS_CONFLICT,
										  grammar,
										  t.token,
										  tokenID+"="+literal,
										  prevAliasLiteralID);
			}
			return; // don't do the alias
		}
		int existingLiteralType = grammar.getTokenType(literal);
		if ( existingLiteralType !=Label.INVALID ) {
			// we've seen this before from a tokenVocab most likely
			// don't assign a new token type; use existingLiteralType.
			tokens.put(tokenID, existingLiteralType);
		}
		String prevAliasTokenID = aliases.get(tokenID);
		if ( prevAliasTokenID!=null ) {
			ErrorManager.grammarError(ErrorManager.MSG_TOKEN_ALIAS_REASSIGNMENT,
									  grammar,
									  t.token,
									  tokenID+"="+literal,
									  prevAliasTokenID);
			return; // don't do the alias
		}
		aliases.put(tokenID, literal);
		aliasesReverseIndex.put(literal, tokenID);
	}

    @Override
	public void defineTokens(Grammar root) {
/*
	System.out.println("stringLiterals="+stringLiterals);
	System.out.println("tokens="+tokens);
	System.out.println("aliases="+aliases);
	System.out.println("aliasesReverseIndex="+aliasesReverseIndex);
*/

		assignTokenIDTypes(root);

		aliasTokenIDsAndLiterals(root);

		assignStringTypes(root);

/*
	System.out.println("stringLiterals="+stringLiterals);
	System.out.println("tokens="+tokens);
	System.out.println("aliases="+aliases);
*/
		defineTokenNamesAndLiteralsInGrammar(root);
	}

/*
protected void defineStringLiteralsFromDelegates() {
	 if ( grammar.getGrammarIsMaster() && grammar.type==Grammar.COMBINED ) {
		 List<Grammar> delegates = grammar.getDelegates();
		 System.out.println("delegates in master combined: "+delegates);
		 for (int i = 0; i < delegates.size(); i++) {
			 Grammar d = (Grammar) delegates.get(i);
			 Set<String> literals = d.getStringLiterals();
			 for (Iterator it = literals.iterator(); it.hasNext();) {
				 String literal = (String) it.next();
				 System.out.println("literal "+literal);
				 int ttype = grammar.getTokenType(literal);
				 grammar.defineLexerRuleForStringLiteral(literal, ttype);
			 }
		 }
	 }
}
*/

    @Override
	protected void assignStringTypes(Grammar root) {
		// walk string literals assigning types to unassigned ones
		Set s = stringLiterals.keySet();
		for (Iterator it = s.iterator(); it.hasNext();) {
			String lit = (String) it.next();
			Integer oldTypeI = (Integer)stringLiterals.get(lit);
			int oldType = oldTypeI.intValue();
			if ( oldType<Label.MIN_TOKEN_TYPE ) {
				Integer typeI = Utils.integer(root.getNewTokenType());
				stringLiterals.put(lit, typeI);
				// if string referenced in combined grammar parser rule,
				// automatically define in the generated lexer
				root.defineLexerRuleForStringLiteral(lit, typeI.intValue());
			}
		}
	}

    @Override
	protected void aliasTokenIDsAndLiterals(Grammar root) {
		if ( root.type==Grammar.LEXER ) {
			return; // strings/chars are never token types in LEXER
		}
		// walk aliases if any and assign types to aliased literals if literal
		// was referenced
		Set s = aliases.keySet();
		for (Iterator it = s.iterator(); it.hasNext();) {
			String tokenID = (String) it.next();
			String literal = (String)aliases.get(tokenID);
			if ( literal.charAt(0)=='\'' && stringLiterals.get(literal)!=null ) {
				stringLiterals.put(literal, tokens.get(tokenID));
				// an alias still means you need a lexer rule for it
				Integer typeI = (Integer)tokens.get(tokenID);
				if ( !tokenRuleDefs.contains(tokenID) ) {
					root.defineLexerRuleForAliasedStringLiteral(tokenID, literal, typeI.intValue());
				}
			}
		}
	}

    @Override
	protected void assignTokenIDTypes(Grammar root) {
		// walk token names, assigning values if unassigned
		Set s = tokens.keySet();
		for (Iterator it = s.iterator(); it.hasNext();) {
			String tokenID = (String) it.next();
			if ( tokens.get(tokenID)==UNASSIGNED ) {
				tokens.put(tokenID, Utils.integer(root.getNewTokenType()));
			}
		}
	}

    @Override
	protected void defineTokenNamesAndLiteralsInGrammar(Grammar root) {
		Set s = tokens.keySet();
		for (Iterator it = s.iterator(); it.hasNext();) {
			String tokenID = (String) it.next();
			int ttype = ((Integer)tokens.get(tokenID)).intValue();
			root.defineToken(tokenID, ttype);
		}
		s = stringLiterals.keySet();
		for (Iterator it = s.iterator(); it.hasNext();) {
			String lit = (String) it.next();
			int ttype = ((Integer)stringLiterals.get(lit)).intValue();
			root.defineToken(lit, ttype);
		}
	}

}
